Extracting agent and method for separating rhenium in industrial wastewater by using same

Abstract

The invention provides an extracting agent and a method for separating rhenium in industrial wastewater, and belongs to the field of purification of heavy metals in the industrial wastewater. Isosorbide serves as a raw material of the extracting agent, a binary ring of the extracting agent is of a V-shaped structure, the V-shaped structure serves as a molecular skeleton of the extracting agent, and nitrogen atoms are introduced; three chain-like aliphatic alkyl groups are connected to a nitrogen atom through a quaternization reaction, and directional regulation and control of the surface hydrophobicity of the extraction agent can be realized by controlling the length of the chain-like aliphatic alkyl groups. By changing the types of derivatization functional groups, the chain segment length of the functional groups, the molecular main chain structure and regulating and controlling the steric hindrance of the molecular main chain structure, the interface reaction of the extraction agent between the organic phase and the inorganic phase is facilitated, and the contact between the activation sites in the molecular structure of the extraction agent in the organic phase and the target metal ions in the inorganic phase is ensured; efficient selective extraction of rhenium is achieved, and the co-extraction phenomenon of other impurity metal ions is avoided to the maximum extent.

Description

Technical Field

[0001] The invention relates to the technical field of heavy metal purification in industrial wastewater, and in particular to an extractant and a method for separating rhenium in industrial wastewater. Background Art

[0002] At present, the mainstream process for purifying heavy metal pollution in water bodies is extraction. The extraction process is widely used in the field of remediation of polluted water bodies due to its simple process operation and strong applicability. The technical core of the extraction method is the optimization of the type of extractant, which not only achieves efficient extraction of the target metal ions, but also takes into account the selective extraction of the target metal ions. However, the extractants currently used to treat heavy metal-containing wastewater have some limitations, especially in terms of selectivity. It is difficult to achieve selective extraction of target metal ions in complex metal solutions. During the extraction stage, a large number of other metal ions are co-extracted, especially tungsten, molybdenum, and rhenium, which are difficult to achieve selective extraction.

[0003] In view of this, it is necessary to design an improved extractant and a method for separating rhenium from industrial wastewater to solve the above problems. Summary of the invention

[0004] In view of the technical problems existing in the background technology, the present application provides an extractant and a method for separating rhenium from industrial wastewater, aiming to solve the technical problem that existing extractants are difficult to achieve selective extraction of target metal ions in complex metal solutions.

[0005] In a first aspect, the present application provides an extractant, the general structural formula of the extractant is: Among them, 0≤n≤7.

[0006] In a second aspect, the present application provides a method for separating rhenium from industrial wastewater using an extractant, wherein the extractant described in the first aspect is used for extraction, and the method comprises the following steps: The extractant is mixed with sulfonated kerosene and dissolved by ultrasonication to obtain a dilute solution; Adding a pH regulator to the rhenium-containing wastewater to adjust the pH value of the solution to a predetermined range, then adding the diluent, oscillating in a water bath for a predetermined time, and selectively extracting rhenium from the solution; The organic phase is separated, the concentration of rhenium in the inorganic liquid phase solution is detected, and the extraction rate of the extractant is calculated.

[0007] As a further improvement of the present application, the volume ratio of the extractant to the sulfonated kerosene is 1:(10-100).

[0008] As a further improvement of the present application, the rhenium is in the solution as ReO4 - Form exists.

[0009] As a further improvement of the present application, the pH regulator is hydrochloric acid.

[0010] As a further improvement of the present application, the rhenium-containing wastewater includes one or more of a rhenium-containing ore solution, a rhenium-containing catalyst waste liquid, and a rhenium-containing metallurgical waste liquid.

[0011] As a further improvement of the present application, the predetermined range of the pH value is 1-4.

[0012] As a further improvement of the present application, the temperature of the water bath oscillation is 25-28° C., and the time is 5-10 min.

[0013] As a further improvement of the present application, the volume ratio of the rhenium-containing wastewater to the diluent is 1:(1~2).

[0014] The beneficial effects of this application are: The present application provides an extractant and a method for separating rhenium from industrial wastewater. The extractant uses isosorbide as a raw material. The presence of oxygen heteroatoms on the V-shaped molecular skeleton structure in the molecular structure is conducive to stabilizing N + The endo-OH in the V-shaped molecular skeleton structure is beneficial to improving the hydrophilicity of the extractant. The three chain aliphatic alkyl groups directly connected to the N atom are effective in achieving the central site (N + ) activation, the surface hydrophobicity of the extractant can be directional regulated by controlling the length of the chain aliphatic alkyl group.

[0015] By changing the type of derivatized functional groups, the length of the functional group chain segments, the molecular main chain structure and its steric hindrance, the interface reaction of the extractant at the organic phase and the inorganic phase is facilitated, ensuring the contact between the activated sites in the molecular structure of the extractant in the organic phase and the target metal ions in the inorganic phase. Finally, a heterogeneous interface-chelating reaction is achieved, which realizes a qualitative change in the chelating effect of the target metal ions, thereby achieving efficient and selective extraction of rhenium and avoiding the co-extraction of other impurity metal ions to the greatest extent.

[0016] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings used in the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 This is a schematic diagram of the synthetic route of the extractant provided in this application. DETAILED DESCRIPTION

[0019] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0021] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0022] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0023] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0024] Existing extractants used in the field of heavy metal wastewater treatment have certain limitations. It is difficult to achieve the selective extraction of target metal ions in complex metal solutions. During the extraction stage, a large number of other metal ions are co-extracted, especially tungsten, molybdenum and rhenium, which are difficult to achieve selective extraction.

[0025] In order to solve the technical problem that existing extractants are difficult to achieve selective extraction of target metal ions in complex metal solutions, the present application provides an extractant and a method for separating rhenium from industrial wastewater, wherein the extractant uses isosorbide as a raw material, and its binary ring has a V-shaped structure. The V-shaped structure is introduced into the nitrogen atom as the molecular skeleton of the extractant, and three chain aliphatic alkyl groups are connected to the N atom through a quaternization reaction, thereby obtaining an extractant with a high-efficiency extraction effect on rhenium in wastewater.

[0026] In a first aspect, the present invention provides an extractant having a general structural formula of: Among them, 0≤n≤7.

[0027] In the technical solution of the embodiment of the present application, the extractant uses isosorbide as a raw material. Isosorbide is a cyclic carbohydrate-derived diol. Its unique spatial stereoscopic structure (the two-membered ring is in a V-shaped structure) leads to the difference between isosorbide and other cyclic carbohydrate-derived diols. The V-shaped structure is used as the molecular skeleton of the extractant. The chemical activity of the two hydroxyl groups (endo-OH and exo-OH) in the V-shaped molecular skeleton structure is different. The exo-OH is derivatized, and then a nitrogen atom is introduced to make it a quaternary ammonium salt through a quaternization reaction, thereby activating the central site (N + The presence of oxygen atoms in the V-shaped molecular skeleton structure is conducive to stabilizing N + The endo-OH in the V-shaped molecular skeleton structure is beneficial to improving the hydrophilicity of the extractant. The three chain aliphatic alkyl groups directly connected to the N atom realize the central site (N + ) activation, by controlling the length of the chain aliphatic alkyl group (the value of n), the directional regulation of the surface hydrophobicity of the extractant can be achieved. By changing the type of derivatized functional groups, the length of the functional group chain segments, the molecular main chain structure and its steric hindrance, it is beneficial for the extractant to react at the interface between the organic phase and the inorganic phase, ensuring the contact between the activated sites in the molecular structure of the extractant in the organic phase and the target metal ions in the inorganic phase, and finally achieving a heterogeneous interface-chelation reaction, achieving a qualitative change in the chelation effect of the target metal ions, and then achieving the purpose of selective extraction of rhenium.

[0028] The preparation method of the extractant provided in the present application is as follows: Figure 1 As shown, the following steps are included: S1. Add isosorbide to the thionyl chloride solution to prepare an isosorbide solution with a concentration of 0.05-0.2 mol / L, add sodium hydroxide with a concentration of 0.05-0.1 mol / L, maintain the system temperature in the range of 0-50°C, react for 24-48 hours, and after the reaction is completed, filter and collect the colorless crystalline product (compound A); S2. Sodium cyanide and compound A are added to a sufficient amount of methanol in a molar ratio of (1-1.1):1, and sodium hydroxide with a concentration of 0.05-0.1 mol / L is added, and the mixture is reacted at room temperature for 2-6 hours. After the reaction is completed, the methanol solvent is removed by rotary evaporation under reduced pressure, and a light yellow powder is collected. Deionized water is added, and the mixture is ultrasonically dissolved, filtered, and inorganic matter is removed. Methanol and deionized water with a volume ratio of 1:1 are added, and the organic phase is collected. The mixture is dried over anhydrous magnesium sulfate, filtered, and the liquid phase is collected. The solvent is removed by rotary evaporation to obtain a white crystalline product (compound B); S3. Compound B is dissolved in an excess of anhydrous tetrahydrofuran solution to prepare a compound B solution with a concentration of 0.05-0.2 mol / L, and then 10-50 g of sodium borohydride is dissolved in anhydrous tetrahydrofuran solution, ultrasonically dissolved, and a suspension of sodium borohydride is prepared. Under the protection of a nitrogen atmosphere, the suspension of sodium borohydride is added dropwise to the compound B solution using a constant pressure titration funnel. The reaction is carried out at room temperature for 2-8 hours. After the reaction is completed, the compound is quenched with a tetrahydrofuran-water solution with a volume ratio of 1:1 in an ice water bath. After the quenching is completed, the liquid is filtered and collected, and the liquid is subjected to reduced pressure distillation to remove the tetrahydrofuran-water solution, and an oily solid (compound C) is collected; S4. Add compound C and chloroalkane to anhydrous ethanol in a molar ratio of 1:(5-8), with the molar concentration of chloroalkane being 1-1.6 mol / L. React at 50-100°C for 24-72 hours. After the reaction, remove the solvent by rotary distillation under reduced pressure. Wash the remaining viscous material with ether ultrasonically to remove excess reactants. Filter and collect the solid phase. Add deionized water and dissolve it by ultrasonic. Recrystallize it with acetone and dry it with liquid nitrogen to obtain the extractant (compound D).

[0029] In a second aspect, an embodiment of the present application provides a method for separating rhenium from industrial wastewater using an extractant, wherein the extractant described in the first aspect is used for extraction, and the method comprises the following steps: S1. Mixing the extractant with sulfonated kerosene, dissolving by ultrasonication, and obtaining a diluent; S2. Adding a pH adjusting agent to the rhenium-containing wastewater to adjust the pH value of the solution to a predetermined range, and then adding a diluent, shaking in a water bath for a predetermined time, and selectively extracting rhenium from the solution; S3. Separate the organic phase, detect the concentration of rhenium in the inorganic liquid phase solution, and calculate the extraction rate of the extractant.

[0030] Among them, extraction rate (%) = ×100%; Where, C0 is the initial concentration of rhenium in the rhenium-containing wastewater before extraction; C1 is the residual concentration of rhenium in the inorganic liquid phase solution after extraction.

[0031] In the technical solution of the embodiment of the present application, by using a specific extractant mixed with sulfonated kerosene, efficient and selective extraction of rhenium can be achieved, the interference of other metal ions is reduced, and the specificity of the extraction process is improved; by adjusting the pH value of the solution to a predetermined range, the extraction efficiency of rhenium can be optimized, so that the extractant can more effectively extract rhenium from wastewater; the organic phase and the inorganic liquid phase are easy to separate, which is convenient for subsequent treatment and recovery of rhenium, and improves the efficiency and economic benefits of the entire process; by detecting the concentration of rhenium in the inorganic liquid phase, the extraction rate of the extractant can be accurately calculated, providing reliable data support for process optimization and extractant performance evaluation. This method reduces the need for expensive equipment and complex processes, thereby reducing the cost of treating rhenium-containing wastewater and improving cost-effectiveness.

[0032] Furthermore, in some embodiments, the volume ratio of the extractant to the sulfonated kerosene is 1:(10-100).

[0033] In the technical solution of the embodiment of the present application, the highest extraction efficiency can be achieved by adjusting the volume ratio of the extractant to the sulfonated kerosene. Sulfonated kerosene, as a diluent, can improve the fluidity of the mixed solution, making the extraction process more uniform, and helping to improve the extraction speed and effect. While ensuring the extraction effect, by increasing the proportion of sulfonated kerosene, the amount of expensive extractant can be reduced, thereby reducing the processing cost. In addition, sulfonated kerosene helps to stabilize the extractant and prevent it from decomposing or deteriorating during storage and use. Specifically, the power of ultrasonic dissolution is preferably 50~100W, the ultrasonic frequency is preferably 40~60kHz, and the ultrasonic dissolution time is preferably 15~30min.

[0034] Further, in some embodiments, rhenium is present in solution as ReO4 - Form exists.

[0035] In the technical solution of the embodiment of the present application, rhenium is in the form of ReO4 - When it exists in the form of rhenium, the specific extractant of the present application is used for extraction, which can form a stable complex with the rhenate ion, thereby achieving efficient extraction of rhenium.

[0036] Furthermore, in some embodiments, the pH adjuster is hydrochloric acid, and the predetermined range of pH value is 1-4.

[0037] In the technical solution of the embodiment of the present application, maintaining the acidity of the solution helps rhenium to exist in the form of soluble rhenate and prevents rhenium from forming insoluble hydroxide or other precipitates. Specifically, the molar concentration of hydrochloric acid is preferably 0.5-1 mol / L. The extractant provided in the present application has an extraction rate of ReO4 in the range of pH 1-4. - Has higher extraction efficiency.

[0038] Furthermore, in some embodiments, the rhenium-containing wastewater includes one or more of a rhenium-containing ore solution, a rhenium-containing catalyst waste liquid, and a rhenium-containing metallurgical waste liquid.

[0039] Specifically, the rhenium-containing wastewater includes one or more of the rhenium-containing solution produced in the hydrometallurgical process of low-grade molybdenum-rhenium sulfide ore, the acidic rhenium-containing waste liquid produced by consuming platinum-rhenium catalyst in the catalytic refining process, and the rhenium-containing metallurgical waste liquid after acid treatment of smoke dust produced in the molybdenum pyrometallurgical process.

[0040] In the technical solution of the embodiment of the present application, the extractant has good selectivity and can efficiently extract rhenium from complex waste liquid without reacting with other metal ions in the waste liquid, thereby achieving efficient and environmentally friendly rhenium ion removal and resource recovery.

[0041] Furthermore, in some embodiments, the temperature of the water bath oscillation is 25-28° C., and the time is 5-10 min.

[0042] In the technical solution of the embodiment of the present application, the appropriate temperature range and oscillation time can make the extractant fully contact and react with the rhenium ions in the waste liquid, thereby improving the extraction efficiency. Too low a temperature may result in a slow reaction rate between the extractant and the rhenium ions, while too high a temperature may cause a decrease in the selectivity of the extractant or the occurrence of side reactions.

[0043] Furthermore, in some embodiments, the volume ratio of the rhenium-containing wastewater to the diluent is 1:(1-2).

[0044] In the technical solution of the embodiment of the present application, the appropriate volume ratio can ensure that the extractant is in full contact with the rhenium ions in the wastewater to form a stable complex, thereby improving the extraction efficiency.

[0045] Some specific embodiments are listed below. It should be noted that the embodiments described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. If specific techniques or conditions are not specified in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. The reagents or instruments used without specifying the manufacturer are all conventional products that can be obtained commercially.

[0046] Example 1 This embodiment provides an extractant A-1, whose molecular structure is , using extractant A-1 to separate rhenium from industrial wastewater, comprising the following steps: S1. The extractant A-1 and sulfonated kerosene were mixed in a volume ratio of 1:10, and ultrasonically dissolved for 15 min at an ultrasonic power of 50 W and a frequency of 40 kHz to obtain a diluent; S2. The pH value of the rhenium-containing wastewater was adjusted to 1 with hydrochloric acid having a molar concentration of 1 mol / L. Thereafter, 100 ml of the above dilution was weighed and added to 50 ml of the rhenium-containing wastewater at room temperature, and the mixture was shaken in a water bath shaker at 25° C. for 5 min. S3. Separate the organic phase, use ICP-OES (inductively coupled plasma emission spectrometer) to detect the concentration of rhenium in the inorganic liquid phase solution, and calculate the extraction rate of extractant A-1, where the detection error of ICP-OES is ±2%.

[0047] Examples 2-6 and Comparative Example 1 Examples 2-6 and Comparative Example 1 respectively provide a method for separating rhenium from industrial wastewater using an extractant. The extractant A-1 provided in Example 1 is used for extraction. Compared with Example 1, the only difference is that the pH value of the rhenium-containing wastewater is different, as shown in Table 1. The other experimental parameters and conditions are basically the same as those in Example 1 and will not be repeated here.

[0048] As shown in Table 1, the extractant A-1 provided in Example 1 has a high efficiency in extracting rhenium within a specific pH range (1-4), and the extraction effect is more than 95%. When the pH is greater than 4, part of the rhenium in the liquid phase precipitates and cannot be extracted from the solution system, thereby reducing the extraction effect. This indicates that the extractant A-1 has a wide window of use and is particularly suitable for strong acid environments.

[0049] Embodiment 7-14 Examples 7-14 respectively provide a method for separating rhenium from industrial wastewater using an extractant, wherein the extractant A-1 provided in Example 1 is used to extract and separate rhenium from a variety of coexisting ion solutions, and the specific operation steps are as follows: A series of mixed solutions containing rhenium and tungsten, molybdenum, iron, and tin in different concentration ratios were prepared, and 10 ml of the diluted solution of the extractant A-1 provided in Example 1 was added to the above 10 ml of the mixed solution, respectively. After shaking in a water bath at 25 ° C. for 5 minutes, the inorganic liquid phase was taken, and the concentration of each metal ion in the solution was detected by ICP-OES to calculate the extraction rate, wherein the detection error of ICP-OES was ±2%, and the extraction effect is shown in Table 2.

[0050] As shown in Table 2, extractant A-1 has a selective extraction effect on rhenium, but does not extract iron and tin metal ions. The extraction rate of tungsten and molybdenum is less than 10%, which ensures the selective enrichment of rhenium in the extract. Other types of quaternary ammonium salts do not have the above advantages. The main reason is that the unique molecular structure of extractant A-1 and the coordination between functional groups lead to the unique spatial structure of extractant A-1, which achieves the effect of efficient selective extraction of rhenium ions and can realize the selective extraction of complex tungsten, molybdenum and rhenium solutions.

[0051] Embodiment 15 This embodiment provides an extractant A-2, whose molecular structure is , using extractant A-2 to separate rhenium from industrial wastewater, comprising the following steps: S1. The extractant A-2 and sulfonated kerosene were mixed in a volume ratio of 1:10, and ultrasonically dissolved to obtain a dilute solution; S2. The pH value of the rhenium-containing wastewater was adjusted to 1 with hydrochloric acid. Thereafter, 100 ml of the above dilution was weighed and added to 50 ml of the rhenium-containing wastewater at room temperature, and the mixture was shaken in a water bath shaker at 25° C. for 5 min. S3. Separate the organic phase, detect the concentration of rhenium in the inorganic liquid phase solution by ICP-OES, and calculate the extraction rate of extractant A-2, wherein the detection error of ICP-OES is ±2%.

[0052] Examples 16-20 and Comparative Example 2 Examples 16-20 and Comparative Example 2 respectively provide a method for separating rhenium from industrial wastewater with an extractant. The extractant A-2 provided in Example 15 is used for extraction. Compared with Example 15, the only difference is that the pH value of the rhenium-containing wastewater is different, as shown in Table 3. The other experimental parameters and conditions are basically the same as those in Example 15 and will not be repeated here.

[0053] As shown in Table 3, the extractant A-2 provided in Example 15 has a high efficiency in extracting rhenium within a specific pH range (1-4), and the extraction effect is more than 95%. When the pH is greater than 4, part of the rhenium in the liquid phase precipitates and cannot be extracted from the solution system, thereby reducing the extraction effect. The extractant A-2 has a wide application window and is particularly suitable for strong acid environments.

[0054] Examples 21-28 Examples 21-28 respectively provide a method for separating rhenium from industrial wastewater using an extractant, wherein the extractant A-2 provided in Example 15 is used to extract and separate rhenium from a variety of coexisting ion solutions, and the specific operation steps are as follows: A series of mixed solutions containing rhenium and tungsten, molybdenum, iron, and tin in different concentration ratios were prepared, and 10 ml of the diluted solution of the extractant A-2 provided in Example 15 was added to 10 ml of the mixed solution respectively. After oscillation for 5 minutes, the inorganic liquid phase was taken, and the concentration of each metal ion in the solution was detected by ICP-OES to calculate the extraction rate, wherein the detection error of ICP-OES was ±2%, and the extraction effect is shown in Table 4.

[0055] As shown in Table 4, extractant A-2 has a selective extraction effect on rhenium, but does not extract iron and tin metal ions. The extraction rate of tungsten and molybdenum is less than 5%. Due to the unique molecular structure of extractant A-2 and the coordination between functional groups, the unique spatial structure of extractant A-2 is achieved, which realizes the efficient and selective extraction of rhenium ions.

[0056] Embodiment 29 This embodiment provides a method for separating rhenium from industrial wastewater using an extractant. The extractant A-2 provided in Example 15 is used for extraction. Compared with Example 15, the only difference is that the temperature of the water bath oscillation is 28°C and the time is 10 minutes. The other experimental parameters and conditions are basically the same as those in Example 15 and will not be repeated here. After testing, the extraction rate of rhenium is 96%.

[0057] Embodiment 30 This example provides a method for preparing the extractant A-2 in Example 15. The synthetic route is as follows: Figure 1 As shown, the specific steps include: S1. Add isosorbide to a sufficient amount of thionyl chloride solution to prepare an isosorbide solution with a concentration of 0.1 mol / L, and add an appropriate amount of sodium hydroxide with a concentration of 0.05 mol / L. Maintain the system temperature at 25°C and react for 24 hours. After the reaction is completed, filter and collect the colorless crystalline product (Compound A) with a yield of 93%.

[0058] S2. Sodium cyanide and compound A are added to a sufficient amount of methanol in a molar ratio of 1:1, and an appropriate amount of sodium hydroxide is added, the concentration of sodium hydroxide is 0.05 mol / L, and the reaction is carried out at room temperature for 4 hours. After the reaction is completed, the methanol solvent is removed by rotary evaporation under reduced pressure, and the light yellow powder is collected. Deionized water is added, ultrasonic dissolution is performed, and inorganic substances (alkali, salt) are removed by filtration. Finally, methanol and deionized water are added in a volume ratio of 1:1, and the organic phase is collected, dried over anhydrous magnesium sulfate, filtered, and the liquid phase is collected. The solvent is removed by rotary evaporation to obtain a white crystalline product (compound B) with a yield of 86%.

[0059] S3. Dissolve compound B in an excess of anhydrous tetrahydrofuran solution. At this time, the concentration of compound B is 0.1 mol / L. Then, dissolve 20 g of sodium borohydride in anhydrous tetrahydrofuran solution, dissolve it by ultrasonication, and prepare a suspension of sodium borohydride. Under the protection of a nitrogen atmosphere, use a constant pressure titration funnel to drop the tetrahydrofuran suspension of sodium borohydride into the tetrahydrofuran solution of compound B. React for 4 hours at room temperature. After the reaction is completed, quench it with a tetrahydrofuran-water solution with a volume ratio of 1:1 in an ice-water bath. After quenching, filter, collect the liquid, perform vacuum distillation on it, remove the tetrahydrofuran-water solution, and collect the oily solid (compound C), with a yield of 32%.

[0060] S4. Add compound C and chlorooctane to anhydrous ethanol at a molar ratio of 1:5, with a molar concentration of compound C of 0.2 mol / L and a molar concentration of chlorooctane of 1 mol / L. React at 60°C for 48 hours. After the reaction is completed, remove the solvent by rotary distillation under reduced pressure, and wash the remaining viscous material with 100 ml of ether by ultrasonic washing to remove excess reactants and filter. Collect the solid phase, add deionized water, dissolve by ultrasonic, and recrystallize from acetone. Since the product is an orange-yellow oil, dry it with liquid nitrogen to obtain extractant A-2 (compound D) with a yield of 37%. Perform hydrogen nuclear magnetic resonance spectroscopy test on compound D. 1 H NMR (deuterated reagent DMSO, 300 MHz): δ 0.50-1.00 (9H, CH3), 1.00-1.50 (30H, CH2), 1.50-2.00 (6H, CH2), 2.50-3.00 (1H, CH), 3.00-3.50 (8H), 3.50-4.00 (5H), 4.00-4.50 (3H).

[0061] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. An extractant, characterized in that The general structural formula of the extractant is: Among them, 0≤n≤7.

2. A method for separating rhenium from industrial wastewater using an extractant, using the extractant according to claim 1 for extraction, characterized in that: The following steps are involved: The extractant is mixed with sulfonated kerosene and dissolved by ultrasonication to obtain a dilute solution; Adding a pH regulator to the rhenium-containing wastewater to adjust the pH value of the solution to a predetermined range, then adding the diluent, oscillating in a water bath for a predetermined time, and selectively extracting rhenium from the solution; The organic phase is separated, the concentration of rhenium in the inorganic liquid phase solution is detected, and the extraction rate of the extractant is calculated.

3. The method for separating rhenium from industrial wastewater by an extractant according to claim 2, characterized in that: The volume ratio of the extractant to the sulfonated kerosene is 1:(10-100).

4. The method for separating rhenium from industrial wastewater by an extractant according to claim 2, characterized in that: The rhenium is in the solution as ReO4 - Form exists.

5. The method for separating rhenium from industrial wastewater by an extractant according to claim 2, characterized in that: The pH adjuster is hydrochloric acid.

6. The method for separating rhenium from industrial wastewater by an extractant according to claim 5, characterized in that: The rhenium-containing wastewater includes one or more of rhenium-containing ore solution, rhenium-containing catalyst waste liquid and rhenium-containing metallurgical waste liquid.

7. The method for separating rhenium from industrial wastewater by an extractant according to claim 5, characterized in that: The predetermined range of the pH value is 1-4.

8. The method for separating rhenium from industrial wastewater by an extractant according to claim 2, characterized in that: The temperature of the water bath oscillation is 25-28° C., and the time is 5-10 min.

9. The method for separating rhenium from industrial wastewater by an extractant according to claim 2, characterized in that: The volume ratio of the rhenium-containing wastewater to the diluent is 1:(1-2).

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